/*
 * Copyright 2002-2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.springframework.security.web.authentication.preauth;

import javax.servlet.http.HttpServletRequest;

import org.springframework.util.Assert;

public class RequestAttributeAuthenticationFilter extends AbstractPreAuthenticatedProcessingFilter {
    private String principalEnvironmentVariable = "REMOTE_USER";
    private String credentialsEnvironmentVariable;
    private boolean exceptionIfVariableMissing = true;

    protected Object getPreAuthenticatedPrincipal(HttpServletRequest request) {
        String principal = (String) request.getAttribute(principalEnvironmentVariable);
        if (principal == null && exceptionIfVariableMissing) {
            throw new PreAuthenticatedCredentialsNotFoundException(principalEnvironmentVariable + " variable not found in request.");
        }
        return principal;
    }

    protected Object getPreAuthenticatedCredentials(HttpServletRequest request) {
        if (credentialsEnvironmentVariable != null) {
            return request.getAttribute(credentialsEnvironmentVariable);
        }
        return "N/A";
    }

    public void setPrincipalEnvironmentVariable(String principalEnvironmentVariable) {
        Assert.hasText(principalEnvironmentVariable, "principalEnvironmentVariable must not be empty or null");
        this.principalEnvironmentVariable = principalEnvironmentVariable;
    }

    public void setCredentialsEnvironmentVariable(String credentialsEnvironmentVariable) {
        Assert.hasText(credentialsEnvironmentVariable, "credentialsEnvironmentVariable must not be empty or null");
        this.credentialsEnvironmentVariable = credentialsEnvironmentVariable;
    }

    public void setExceptionIfVariableMissing(boolean exceptionIfVariableMissing) {
        this.exceptionIfVariableMissing = exceptionIfVariableMissing;
    }
}
